It's the most classic of no-bake cake recipes, loved for its sweet flavour and distinct crunch, and yet many people don't know how to make rocky road. The traditional recipe calls for milk chocolate, butter, golden syrup, mini marshmallows, and digestive biscuits — almost like a hybrid cake and flapjack. Anyone looking for a standout recipe to make this sweet delight at home should look no further than Mary Berry's formula.

She uses all of the core ingredients plus one small addition that levels up the crunchiness and flavour profile of standard rocky road. Sharing her expert formula from the cookbook Cook and Share, Mary said she described the fridge cake as "super simple", noting that it's a "real crowd pleaser" for kids and adults alike. And the chocolatey treat is perfect to accompany a bitter coffee.

Mary's secret ingredient is honeycomb, a light and airy sweet typically made from sugar, golden syrup (or honey) and bicarbonate of soda.

The slightly fluffy texture and sweet flavour of the honeycomb contrast with the chocolatey casing, for which Mary uses dark chocolate in addition to milk chocolate. She also forgoes marshmallows, which are typically added to provide a softness to the quirky textures in rocky road.

It means the recipe is simpler than most, with just five ingredients.

Rocky road recipe

Ingredients

• 400g/14oz milk chocolate, broken into pieces
• 225g/8oz butter, cubed, plus extra for greasing
• Six tbsp golden syrup
• 75g/3oz dark chocolate (approx. 52% cocoa solids), broken into pieces
• 500g/1lb 2oz digestive biscuits, roughly crushed to nut-sized pieces
• Four 32g chocolate-coated honeycomb bars, cut into bite-sized pieces

Method

This recipe requires minimal preparation. You just need to chop the ingredients and melt the chocolate with the butter and syrup.

It's also worth greasing and lining a 30x23cm/12x9 in traybake tin with baking paper.

First, place the broken-up milk chocolate pieces in a large heatproof bowl and add the butter and syrup. Place the bowl over a pan of simmering water and heat gently, stirring until melted.

Add the dark chocolate to a small heatproof bowl and place the bowl over simmering water until melted.

Add the crushed biscuits to the milk chocolate mixture and fold together until well coated, then spoon into the prepared tin.

Sprinkle over the chunks of honeycomb and press down firmly. Finally, drizzle with the melted dark chocolate in a zig-zag pattern.

Allow the mixture to chill in the fridge for two hours until firm. When set, slice the rocky road into 24 squares to serve.